package com.hmdp.service.impl;

import cn.hutool.core.bean.BeanUtil;
import com.hmdp.config.RedissonConfig;
import com.hmdp.dto.Result;
import com.hmdp.entity.SeckillVoucher;
import com.hmdp.entity.VoucherOrder;
import com.hmdp.mapper.VoucherOrderMapper;
import com.hmdp.service.ISeckillVoucherService;
import com.hmdp.service.IVoucherOrderService;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.hmdp.utils.RedisIdWorker;
import com.hmdp.utils.SimpleRedisLock;
import com.hmdp.utils.UserHolder;
import lombok.extern.slf4j.Slf4j;
import org.redisson.api.RLock;
import org.redisson.api.RedissonClient;
import org.springframework.aop.framework.AopContext;
import org.springframework.core.io.ClassPathResource;
import org.springframework.data.redis.connection.stream.*;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.data.redis.core.script.DefaultRedisScript;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

import javax.annotation.PostConstruct;
import javax.annotation.Resource;
import java.time.Duration;
import java.time.LocalDateTime;
import java.util.Collections;
import java.util.List;
import java.util.Map;
import java.util.concurrent.ArrayBlockingQueue;
import java.util.concurrent.BlockingQueue;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;

/**
 * <p>
 *  服务实现类
 * </p>
 *
 * @author 虎哥
 * @since 2021-12-22
 */
@Slf4j
@Service
public class VoucherOrderServiceImpl extends ServiceImpl<VoucherOrderMapper, VoucherOrder> implements IVoucherOrderService {
    @Resource
    private ISeckillVoucherService seckillVoucherService;
    @Resource
    private RedisIdWorker redisIdWorker;
    @Resource
    private StringRedisTemplate stringRedisTemplate;
    @Resource
    private RedissonClient redissonClient;
    private static final DefaultRedisScript<Long> SECKILL_SCRIPT;
    static {
        SECKILL_SCRIPT = new DefaultRedisScript<>();
        SECKILL_SCRIPT.setLocation(new ClassPathResource("seckill.lua"));
        SECKILL_SCRIPT.setResultType(Long.class);
    }

    //创建一个线程池
    private static final ExecutorService SECKILL_ORDER_EXECUTOR = Executors.newSingleThreadExecutor();


@PostConstruct
    private  void init() {
        SECKILL_ORDER_EXECUTOR.submit(new Thread(new VoucherOrderHandler()));
    }
    private  class VoucherOrderHandler implements Runnable {
    String queueName = "stream.orders";
        @Override
        public void run() {
            while (true) {
                try {

                    // 1.获取消息队列中的订单信息 XREADGROUP GROUP g1 c1 COUNT 1 BLOCK 2000 STREAMS s1 >
                    List<MapRecord<String, Object, Object>> list = stringRedisTemplate.opsForStream().read(
                            Consumer.from("g1", "c1"),
                            StreamReadOptions.empty().count(1).block(Duration.ofSeconds(2)),
                            StreamOffset.create(queueName, ReadOffset.lastConsumed())
                    );
                    // 2.判断订单信息是否为空
                    if (list == null || list.isEmpty()) {
                        // 如果为null，说明没有消息，继续下一次循环
                        continue;
                    }
                    // 解析数据
                    MapRecord<String, Object, Object> record = list.get(0);
                    Map<Object, Object> value = record.getValue();
                    VoucherOrder voucherOrder = BeanUtil.fillBeanWithMap(value, new VoucherOrder(), true);
                    // 3.创建订单
                    handleVoucherOrder(voucherOrder);
                    // 4.确认消息 XACK
                    stringRedisTemplate.opsForStream().acknowledge(queueName, "g1", record.getId());
                } catch (Exception e) {
                    log.error("处理订单异常", e);
                    //处理异常消息
                    handlePendingList();
                }
            }
        }
    }
    private void handlePendingList() {
        while (true) {
            try {
                // 1.获取pending-list中的订单信息 XREADGROUP GROUP g1 c1 COUNT 1 BLOCK 2000 STREAMS s1 0
                List<MapRecord<String, Object, Object>> list = stringRedisTemplate.opsForStream().read(
                        Consumer.from("g1", "c1"),
                        StreamReadOptions.empty().count(1),
                        StreamOffset.create("stream.orders", ReadOffset.from("0"))
                );
                // 2.判断订单信息是否为空
                if (list == null || list.isEmpty()) {
                    // 如果为null，说明没有异常消息，结束循环
                    break;
                }
                // 解析数据
                MapRecord<String, Object, Object> record = list.get(0);
                Map<Object, Object> value = record.getValue();
                VoucherOrder voucherOrder = BeanUtil.fillBeanWithMap(value, new VoucherOrder(), true);
                // 3.创建订单
                createVoucherOrder(voucherOrder);
                // 4.确认消息 XACK
                stringRedisTemplate.opsForStream().acknowledge("stream.orders", "g1", record.getId());
            } catch (Exception e) {
                log.error("处理pendding订单异常", e);
                try{
                    Thread.sleep(20);
                }catch(Exception ex){
                    ex.printStackTrace();
                }
            }
        }
    }

    private void handleVoucherOrder(VoucherOrder voucherOrder) {
        //获取用户
        Long userId = voucherOrder.getUserId();
    //创建锁对象
     //  SimpleRedisLock lock = new SimpleRedisLock("order:" + userId, stringRedisTemplate);
       RLock lock = redissonClient.getLock("lock:order:" + userId);

       //获取锁
       boolean isLock = lock.tryLock();
       if (!isLock) {
           //获取锁失败，返回失败
           log.error("获取锁失败");
           return;
       }
       try {
            proxy.createVoucherOrder(voucherOrder);
       }finally {
            //释放锁
            lock.unlock();
        }
    }
    private IVoucherOrderService proxy;

    @Override
    public Result seckillVoucher(Long voucherId) {
        //获取用户
        Long userId = UserHolder.getUser().getId();
        long orderId = redisIdWorker.nextId("order");
        // 1.执行lua脚本
        Long result = stringRedisTemplate.execute(
                SECKILL_SCRIPT,
                Collections.emptyList(),
                voucherId.toString(), userId.toString(),String.valueOf(orderId)
        );
        int r = result.intValue();
        // 2.判断结果是否为0
        if (r != 0) {
            // 2.1.不为0 ，代表没有购买资格
            return Result.fail(r == 1 ? "库存不足" : "不能重复下单");
        }

        //获取代理对象
        proxy = (IVoucherOrderService) AopContext.currentProxy();

        // 3.返回订单id
        return Result.ok(orderId);
    }

//    @Override
//    public Result seckillVoucher(Long voucherId) {
//        //查询优惠券
//        SeckillVoucher voucher = seckillVoucherService.getById(voucherId);
//        //判断秒杀是否开始
//        if (voucher.getBeginTime().isAfter(LocalDateTime.now())) {
//            return Result.fail("秒杀尚未开始");
//        }
//        //判断秒杀是否结束
//        if (voucher.getEndTime().isBefore(LocalDateTime.now())) {
//            return Result.fail("秒杀已结束");
//        }
//        //判断库存是否充足
//        if (voucher.getStock() < 1) {
//            return Result.fail("库存不足");
//
//        }
//        Long userId = UserHolder.getUser().getId();
//     //创建锁对象
//      //  SimpleRedisLock lock = new SimpleRedisLock("order:" + userId, stringRedisTemplate);
//        RLock lock = redissonClient.getLock("lock:order:" + userId);
//
//        //获取锁
//        boolean isLock = lock.tryLock();
//        if (!isLock) {
//            //获取锁失败，返回失败
//            return Result.fail("不允许重复下单");
//        }
//        try {
//            //获取代理对象
//            IVoucherOrderService proxy = (IVoucherOrderService)AopContext.currentProxy();
//            return  proxy.createVoucherOrder(voucherId);
//        }finally {
//            //释放锁
//            lock.unlock();
//        }
//    }
    @Transactional
    public   void  createVoucherOrder(VoucherOrder voucherOrder) {
        Long userId =  voucherOrder.getUserId();
        //一人一单策略
        // 5.1.查询订单
        int count = query().eq("user_id", userId).eq("voucher_id",  voucherOrder.getVoucherId()).count();
        // 5.2.判断是否存在
        if (count > 0) {
            // 用户已经购买过了
             log.error("用户已经购买过一次");
        }

        // 6.扣减库存
        boolean success = seckillVoucherService.update()
                .setSql("stock = stock - 1") // set stock = stock - 1
                .eq("voucher_id", voucherOrder.getVoucherId()).gt("stock", 0) // where id = ? and stock > 0
                .update();
        if (!success) {
            // 扣减失败
            log.error("库存不足");
            return;
        }


        save(voucherOrder);


    }

}
